Alternating piston pump



4 Sheets-Sheet 1 Filed Jan. 17, 1946 INVENTOR.

JAMES P. JOHNS ATTORNEYS Filed Jan. 17, 1946 March 29, 1949. J. P. JOHNSON 2,465,878

ALTERNATING PISTON PUMP 4 Sheets-Sheet 2 INVENTOR. JAMES P.JOHNSON ATTORNEYS March 29, 1949. P JOHNSON 2,465,878

ALTERNATING PI STON PUMP 4 Sheets-Sheet 3 Filed Jan. 17, 1946 INVENTOR. JAMES P. JOHNSON ATTORNEYS March 29, 1949. I JNP. JOHNSON 2,465,878

ALTERNATING PISTON PUMP Filed Jan. 17, 1946 4 Sheets-Sheet 4 INVENTOR.

JAMES RJOHNSON ATTORNEYS Patented Mar. 29, 1949 UNITED STATES PATEEZT ()FFICE ALTERNATING PISTON PUMP James P. Johnson, Shaker Heights, Ohio Application January 17, 1946, Serial No. 641,743

1 Claim. 1

This invention relates to pumps and more particularly to vane type pumps in which the vanes are movable relative to one another to provide the variable volume fluid chamber which is essential in all pumps to eifect suction and discharge cycles. Heretofore, such a variable volume fluid chamber has been provided either by oscillation of a vane relative to a fined abutment having valved passages adjacent each side thereof or by varying the radial dimension of said chamber. In the present invention it is proposed to accomplish such end without the use of said valved pass-ages or without Varying the radial dimension of said chamber.

Therefore, it is an object of this invention to provide a pump having novel means for effecting displacement of fluid thereinto and therefrom. Another object of this invention is to provide a pump in which the loads on the bearings, due to fluid pressure, are balanced or cancelled. Another object is to provide in a pump a novel vane construction and vane assembly. Still another object is the provision of a novel driving means for effecting rotation of the vanes and movement thereof relative to one another. Still another object of this invention is to provide driving means which are readily adapted. to be provided with adjusting means to vary the amount of displacement of the pump per revolution of the vanes. Another object of this invention is the provision of a novel passage arrangement wherein the passages are disposed in the end walls of a cylindrical pump chamber. Another object of this invention is to provide a pump in which the driving means can be rotated in either of two directions. Another object of this invention is to provide a pump which is simple in construction and eifi- -cient in operation and which has only two moving parts within the pumping chamber.

Additional objects and advantages of this invention shall become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the 1 features hereinafter fully described and particularly pointed out in the claim, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In the drawings:

Fig. 1 is a longitudinal sectional View of one form of the invention;

Fig. 2 is a cross sectional view taken along line 2-2 of Fig. 1;

Fig. 3 is a cross sectional view taken along line 3-3 of Fig. 1;

Fig. 4 is an end view of the device shown in Fig. 1 as viewed from the left-hand end thereof;

Fig. 5 is a perspective view of the vanes;

Figs. 6-10 are schematic drawings of the invention shown in Fig. 1 illustrating the relative positions of the vanes during one revolution thereof;

Fig. 11 is a schematic drawing of the invention shown in Fig. 1 but with a modified form of groove in the driving means;

Figs. 12-16 are schematic drawings of a modified form of driving means illustrating such driving means in. various positions; and

Figs. 17-21 are schematic drawings similar to Figs. 12-16 but difiering therefrom in that the driving means have been shifted to a difierent position relative to the axis of the vanes.

Referring to the drawings and first to Figs. 1-5, this pump comprises a body [0 having a cylindrical chamber H therein defined by a bore 12 and spaced end walls It and I4. End wall I3 is an integral part of the body II] and end wall I4 is part of a port adapter l5 which is secured to the body. Port adapter I5 is provided with two ports l6 and I1. Port H is in communication with a cored passage 23 which terminates at the end wall it in two openings l8 and i9 diametrically opposite one another. Port H5 is in communication with a passage 2| disposed longitudinally along one side of the body Ill and a cored passage 22 which terminates in end wall I3 in two openings 23 and 24, also diametrically opposed to one another, as are openings [8 and [9 but 90 out of phase therefrom.

Mounted for rotation within chamber II are two vanes 25. Each vane, as clearly shown in Fig. 5, comprises a central hollow hub portion 26 and two diametrically opposed web portions 21, extending radially therefrom and projecting longitudinally therebeyond. The web portions 21 at the hub 26 are of thickness less than the diameter of the hub so that the longitudinally projecting portions of one vane can overlie the exposed portions of the hub of the other vane and yet provide for relative rotation between the two vanes. In other words, in making the web portions 2! of generally segmental cross section, as shown, the sum of the included angles of the four webs is less than 360, whereby segmental spaces are left between adjacent faces of said webs. The inner surface 28 of each longitudinal- 1y projecting portion of the web 21 is preferably cylindrical and of diameter equal to the diameter of the hub on the other vane, although surface 28 could be fiat or of other shape just so long as it :slid'ably engages the hub on the other vane.

In assembled position, the vanes 25 are, nested one within the other with the hub ends 29 in abutting and sealing relation with one another and the longitudinally projecting portions of the webs 21 of one vane overlying and in sealing relation with the hub 26 of the other vane. Thus. in such assembled position, there are provided four segmental spaces between the vanes defined by adjacent faces of the webs 21. When the vanes are rotated relative to one another, two of such segmental spaces will become larger and two will become smaller. That is, the included angles between adjacent faces of the webs 27! which define said spaces will increase and decrease respectively. Each vane 25 has surfaces thereof in sealing relation with end walls I? and I4 and bore l2 of chamber H. Also, inasmuch as the vanes are disposed in sealed relation with one another, fluid contained in one pair of segmental spaces cannot leak into the other pair of segmental spaces.

Secured in driving relation to one vane 25 is a shaft 30 which passes through the hub 26 of the other vane. Secured in driving relation to the other vane 25 is a hollow shaft 3| which surrounds shaft 30 and has a free running fit thereon. Shafts 30 and 3! are .iournaled in bearings 32 and 33 respectively. The axis of rotation of such shafts is coincidental with that of bore l2. Each shaft projecting arm portion 3d integral therewith, at the end of each of which is mounted a roller 35 having an axis parallel to the axis about which said shafts 30 and 3! rotate. The arms 34 are adjacent one another to permit rotation of one relative to the other.

Secured to the body I is a drive housing 36 in which a drive plate 31 is rotatably mounted about an axis eccentric of the axis of bore I 2. The face of drive plate 31 is provided with a circular groove 38 located eccentric of the axis of rotation of said drive plate. Groove 38 is of radial width, equal to the diameter of the rollers 35. Rollers 35 are disposed to project into said groove and into engagement with said groove.

The manner in which the driving means, which comprises the drive plate 3?, groove 38. rollers 35, arms 34 and shafts 30 and 3!, effects rotation of the vanes 25 within chamber I l and movement of the vanes relative to one another during such rotation can best be seen by referring to Figs. 6-10, which schematically show the relation of the parts at various intervals of one complete revolution of the drive plate 3'1. For the sake of clarity, adjacent faces of the vanes are numbered l-2, 3-4, 5B, l8. In Fig. 6, the faces l2 and 3-4 are in engagement and faces 5-5, '!-8 are spaced apart. Now, in

rotating the drive plate 31 clockwise to the position of Fig. 7, the faces l2, 3-4 are spaced apart and faces 56, !-8 are in engagement. In the position of Fig. 7, the rollers 35 are spaced further apart than in Fig. 6 and as distinguished from a direct driving relationship, one vane has been accelerated with. respect to the other one in that one vane has been rotated more than 90 and the other one less than 90. In rotating the drive plate 3! from the position of Fig. 7 to that of Fig. 8, the faces l2, 3-4, 56, l8 bear the same relation to one another as 30 and 3! has a radially in Fig. 6. except that they have been rotated through 180. Fig. 9 is the same as Fig. 7 except that the vanes have rotated 180 therefrom. Fig. 10 is the same as Fig.6

It will thus be apparent that in one revolution. of the drive plate, each vane has been rotated 360 and each of the four segmental spaces between the vanes has opened and closed twice.

This rotation and movement of the vanes as described above is so related to the openings l8 and i9 and 23 and 24 that when the faces l2 and 3 l are being separated as in going from Fig. 6 to Fig. 7 and from Figs. 8 to 9, fluid from openings I8 and i9 is drawn thereinto and when faces 5-6 and l-8 are moving toward one another, as in going from Figs. 6-7 and from 8-9, the fluid contained therein will be expelled through openings 23, and 24. Likewise, in going from Figs. 7 to 8 and from Figs. 9 to 10, the fluid contained within the spaces between l2 and 3-4 will be expelled from openings 23 and 2d, and the fluid from openings I 8 and I9 will be drawn into the spaces created by separation of faces 5@ and lfi. During rotation of the vanes the end faces thereof overlie the respective openings 48 and IS and 23 and 24 to preclude communication between them. In Figs. 6-10, the faces of the vanes are shown as engaging one another every 180, thus displacing a maximum volume of fluid per revolution. Obviously, if the axis about which the drive plate rotates were shifted closer to the axis of rotation of the vanes, the faces of the vanes would not engage one another but would merely oscillate relative to one another and thereby displace a lesser volume of fluid. Of course, if the axis of rotation of the drive plate were coincidental With that of the vanes, then there would not be any movement of the vanes relative to one another and therefore the device would cease to function as a pump. In the adjusted position of Figs. 6-10, the displacement in one revolution would be eight times that of the volume of one of the segmental spaces between the adjacent faces of the vanes. It is to be noted that by reason of the diametricall opposed relationship of the segmental spaces defined between the vanes, fluid discharged under high pressure will be balanced or cancelled as far as causing an unequal loading on the bearings 32 and 33. Thus, there is no tendency of forcing the vanes into binding engagement with bore I2 or causing excessive wear of the bearings.

In Fig. 11, the drive plate 31 is shown with a modified form of groove 38 which has straight sides. In certain instances, it may be desirable to modify the groove as in Fig. 11, or otherwise shape the groove so as to cause movement of the vanes relative to one another at slightly different rates than those attainable with a circular groove.

Figs. 12-16 illustrate schematically a modified form of driving connection in which a crank 39 and a pair of levers or links 40 have been substituted for the groove 38 and rollers 35 ShOWn in Figs. l-ll. As shown in Figs. 12-16, crank 39 is rotatable about an axis eccentric of the axis of rotation of the vanes. One end of each link 50 is pivotally connected to the outer end of crank 39 and the other end of each link is pivotally connected to one of the arms 34. In Fig. 12, the links are jack-knifed inwardly pulling faces l2 together. In rotatin th crank 39 t the position of Fig. 13, the links 40 are forced into alignment, thus having effected rotation of the vanes and movement of the same relative to one another to separate the faces (-2. In Fig. 14, the links 40 are jack-knifed outwardly, thus drawing faces l2 together and in Fig. 15, the links are again in alignment, thus causing separation of the faces |-2. In Fig. 16, the parts are in the same position as in Fig. 12. As described in relation to Figs. 6-10, the separation and drawing together of the vane faces during rotation of the vanes is correlated with respect to the openings l8 and I9 and 23 and 24 to effect drawing in of fluid into the pump from openings l8 and I9 and expelling fluid from openings 23 and 22.

The structure of Figs. l7-21 is exactly the same as that of Figs. l216 except that the axis of rotation of the crank 39 is coincidental with that of the vanes. As shown in these figures, rotation of the crank merely rotates the vanes and does not eifect any relative movement between the vanes. Therefore, no fluid will be drawn into or expelled from the pump when the crank center is coincidental with the vane axis.

While no particular structure has been illustrated in the accompanying drawings for efiecting variation or adjustment of the displacement of the pump, it will be apparent to those skilled in the art that there are many difierent ways of altering the eccentricity between the axis of rotation of the driving means and the axis of rotation of the vanes.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in the following claim or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

In a pump the combination of a body having a cylindrical bor therein, co-axial vanes rotatably mounted in said bore and defining at least one fluid cavity between said bore and adjacent portions of said vanes, said vanes being movably mounted relative to one another to vary the fluid capacity of said cavity, a shaft connected to and co-axial with each vane, a radially extending arm on each shaft, and driving means connected to said arms for imparting rotation to said vanes and for moving said vanes relative to one another, said driving means being rotatable about an axis eccentric with respect to the axis of said bore and including a circular groove engaging each of said arms, said groove being eccentric of the axis of rotation of said driving means and of the axis of said bore.

JAMES P. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 281,165 Villebonnet July 10, 1883 308,859 1S-tewart Dec. 2, 1884 1,921,747 Greve Aug. 8, 1933 1,991,308 Zens Feb. 12, 1935 2,061,131 Bancroft Nov. 17, 1936 2,270,976 Sobek Jan. 27, 1942 2,394,337 Sobek Feb. 5, 1946 FOREIGN PATENTS Number Country Date 20,816 Great Britain 1890 357,242 Germany Aug. 21, 1922 

